Two nights ago I told Alexa to arm the alarm system before I went to bed. Nothing, Nada, Zip. I use a Smartenit Harmony as an Alexa bridge to my Stargate controller which normally works flawlessly. I tell Alexa to turn something on and the Smartenit Harmony sends an X10 code to trigger the Stargate to do whatever it's supposed to do.
I went through the usual steps of checking connections, rebooting things and even trying a different PLM with the Harmony to no avail. Then I pulled out my trusty XTBM Pro signal sleuth and plugged it into the same outlet as the Harmony. BINGO! It said "HIGH NOISE" which is something I've never seen before. There is a Tivo Roamio on the same circuit as the Harmony so I unplugged the 12v 3a wall wart and the noise disappeared. The wall wart is over 7 years old and still outputs the correct voltage but felt a bit warmer than it should be. I replaced it with a 5 amp power supply and all is well again. What I also noted is that if I plugged the wall wart back in by itself while watching the XTBM, there would be a very brief "HIGH NOISE" reading and then it was OK. If the wall wart was also plugged into the TIVO then the noise remained constant so the load on the wall wart apparently has an effect on the noise level.
The moral of the story is that wall warts can and do go bad - at least from an X10 standpoint - before they completely fail. I've had wall warts cause problems before but this is the first time in 37 years that I've had one change like this.
